1. Field of the Invention
This invention relates to water pumps and, more particularly, to heat-powered water pumps.
2. The Prior Art
Throughout the world there are many places where fuel and power are expensive because of limited fossil fuel deposits, transportation difficulties, extended electrical transmission lines, and the like. Even the production of electrical energy by diesel engines results in an excessive cost for electrical power when considered in light of the costs associated with the initial equipment purchase, fuel, transportation of the fuel, and repairs. In addition, the projected fossil fuel shortages will result in continually increasing fuel costs.
However, cheap and abundant energy is necessary for a high material standard of living. It is only when humanity can multiply mechanical work many times beyond muscle power that enough goods and services can be produced to provide the economic conditions for a reasonably satisfactory standard of living. Although fuel and energy are reasonably available and at a relatively reasonable cost in the currently industrialized areas of the world, in the remote areas of the world the relatively high costs for fuel and energy, particularly electrical energy, substantially inhibits the further development of those portions of the world. For example, vast areas of the world are suitable for irrigation with relatively abundant sources of water being relatively readily available. However, these areas also require an economical technique for raising the water from a relatively shallow water table or nearby stream to the surface for irrigation. Most primitive devices for lifting this water include simple devices operated by one or two men or through the use of animal energy. However, animals consume food grown on irrigated land, part of which might otherwise be used for human food. Additionally, the use of manpower to pump water is particularly wasteful since man's labor can be more economically utilized in providing goods and services rather than mechanical energy.
Coincidentally, although there are many parts of the world where fuel and electrical power are expensive because of long distances from coal or oil deposits, transportation difficulties, or small-scale rather than large-scale operations, these same locations are also endowed with an abundance of available solar energy. On a comparative basis, solar energy does appear to be feasible in providing the necessary energy for the efficient pumping of water. Although solar energy is produced only while the sun is shining, pumping irrigation water, which involves no storage of power, offers a good area for the early use of solar energy. In these situations, the economic comparisons between solar energy and other energy sources appear to be sufficiently advantageous to encourage further research and development of solar energy. In addition, for those times when the sun is not shining, substitute thermal energy could be obtained from burning agricultural wastes such as stubble, chaff and the like.
Various types of water or fluid pumps operable from heat sources are shown in U.S. Pat. Nos. 2,050,391; 2,553,818; 2,688,922; 2,744,470; 2,757,618; 2,954,741; 2,973,715; 3,659,960; 3,765,799; and 3,790,305. However, the devices represented in each of the foregoing patents tend to be either complex, expensive to fabricate and maintain or require excessive monitoring for efficient utilization in the less developed sections of the world.
In view of the foregoing, it would, therefore, be an advancement in the art to provide a heat-powered water pump which is operable to pump water from a relatively shallow location to an elevated location, the pump operating relatively independently of continuous monitoring. In addition, it would be an advancement in the art to provide a heat-powered water pump which can utilize either solar energy or thermal energy from burning agricultural wastes. Such an invention is disclosed and claimed herein.